Wheel cover retention systems including compressible wire springs and/or spring clips are widely used to secure a wheel cover in position on a wheel, particularly where a substantial portion of the wheel cover is plastic. The wire spring is typically characterized by a pluraliy of circumferentially spaced loops which project radially outward into engagement with the wheel. Each loop experiences radially inward loading during installation of the wheel cover. The spring load is typically transmitted to a flexator which interconnects each loop and bows in response to the radial loading of the spring.
The wire spring or spring clip can be mounted on or within a plurality of fingers molded into and extending axially inward from the rear face of the wheel cover. The fingers typically have resilience to experience the radial inward travel necessary to accomplish loading of the spring through the interference fit with the wheel. It is often difficult, however, to install the wheel cover since the force required to compress the spring radially offsets the wheel cover instead of compressing the fingers and the spring. Thus, several attempts at installation are often necessary in order to maintain the wheel cover in the correct axial alignment with the wheel while providing the force necessary to compress the fingers and spring to fit within the wheel. This installation problem is particularly prevalent with wheel ornaments employing higher spring rate retention systems, such as hubcaps.
It is also known to use a plurality of circumferentially spaced ribs in conjunction with the fingers to prevent radial shifting of the wheel cover after the wheel cover has been installed on the wheel and to limit radial and axial movement of the wire relative to the wheel cover. This design typically includes a plurality of spring loaded cam tabs which first contact the wheel during installation, and a plurality of support ribs joined by a circumferential ring including retention means for holding the spring wire and limiting the wires radial motion during and after installation. As with other designs, however, the wheel cover is difficult to install. If the axial force used to install the wheel cover is not evenly distributed over the surface area of the cover (i.e. is off center) it will cause the diametrically opposite portion of the wheel cover to shift radially and climb out of the wheel.
It is therefore one object of the present invention to provide a wheel cover including a retention system which allows for quick and easy installation of the cover on a wheel.
It is another object of the present invention to provide a wheel cover including a retention system which eliminates axial or radial motion of the wheel cover relative to the wheel and establishes a secure fit of the wheel cover on the wheel.
It is another object of the present invention to provide a wheel cover including a retention system which inhibits axial and radial motion of the wire spring relative to the wheel cover during and after installation of the wheel cover on the wheel.
It is yet another object of the present invention to provide a wheel cover including a retention system which inhibits circumferential motion of the wire spring relative to the wheel cover during and after installation of the wheel cover on the wheel.